Combined Solid-State Neutron Gamma High Efficiency Detector

NOVA Scientific proposes Phase II development of a solid-state, high-efficiency neutron detection alternative to 3He gas tubes employing neutron-sensitive microchannel plates (MCPs) containing 10B and/or Gd. This program supports the DNDO development of technologies designed to detect and interdict nuclear weapons or illicit nuclear materials. This solid-state neutron detector would permit operations in wide-ranging environments limited with 3He. The small prototypes resulting from the Phase II effort will be designed and sized to support the Intelligent Personal Radiation Locator (IPRL) hardware. Phase I neutron detection efficiency measurements of greater than 25 percent were rigorously carried out using a 252Cf source. With a surrounding gamma scintillator measuring the instantaneous 478 KeV gamma from the boron-neutron interaction, an electronic coincidence procedure verified a neutron event with high confidence, rejecting spurious counts and interference from gamma photons at a level of 10-4, comparable to the selected 3He tube used as a standard. The objective of Phase II Year 1 is to move the MCP component capability to its projected full potential of 60-75 percent detection efficiency for thermalized neutrons from a fast source and develop the surrounding scintillator system configuration to establish a gamma rejection of 10-5 to 10-6. This would effectively match or exceed 3He tube performance. Additionally a high yield, low noise vacuum encapsulation of the MCP and algorithm peak search will be carried out. Year 2 will assemble repetitive prototypes, establish a breadboard electronics power and data package, and carry out an assessment of pre-commercialization readiness for field operations. NOVA Scientific is teaming with several experts for support; St. Gobain Crystals for expertise in high speed scintillators; VPI Engineering for power and readout electronics and packaging; Sensor Sciences for test and characterization support; and American Electro-Optics for vacuum tube encapsulation.